What do you mean by Huguang filling Sichuan?

In the late Ming and early Qing dynasties, due to the war, the population of Sichuan dropped sharply, and a large number of cultivated land was barren. In order to solve the problems of labor force and grain production in Sichuan, the newly established Qing Dynasty adopted measures of immigration and reclamation. Mainly from more than ten provinces such as Hunan, Guangdong, Guangxi, Jiangxi, Fujian, Shaanxi, Yunnan and Guizhou, they immigrated to Sichuan to settle down and reclaim land. Among them, due to the close distance, the most immigrants are from Hubei and Hunan. At that time, the two lakes were one province, which was called "Huguang Province", so the people called this great immigration "Huguang Filling Sichuan". The Records of Dayi County in Guangxu period of Qing Dynasty recorded: "People from Hunan, Hubei, Jiangxi, Guangdong, Guangxi, Shanxi, Shaanxi and other places went to cities to reclaim wasteland and live together. Macheng has a large population, followed by Jiangxi and Shaanxi, and then Guangdong and Guangxi. The popular saying that' Huguang fills Sichuan' is also evident. "

The wars in Sichuan in the late Ming and early Qing dynasties were as follows: Zhang rebels entered Sichuan three times, and the Ming and Qing armies repeatedly pursued and besieged; The anti-Qing armed forces in Nanming moved to the southwest, attracting the Qing army to chase and intercept; Wu Sangui Rebellion, the Qing army put down the "San Francisco Rebellion", and Sichuan became the battlefield of seesaw battle. Sichuan is located in the hinterland of China, and it is also a rich granary, so the four emperors of Shunzhi, Kangxi, Yongzheng and Qianlong in the early Qing Dynasty attached great importance to the restoration of Sichuan. The main measures taken are large-scale immigration, enjoying the policy of the special zone and tax exemption for three to five years after reclamation. According to the records, the initial immigration activities were forced by the government. Later, immigrants found that Sichuan had fertile land, mild climate and abundant production, so they mobilized their relatives and neighbors to move in. This migration lasted for more than 100 years, and the population entering Sichuan was about one million.